Multiple, closely spaced alternative 5' exons in the DmCKIIbeta gene of Drosophila melanogaster
Multiple, closely spaced alternative 5' exons in the DmCKIIbeta gene of Drosophila melanogaster
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DOI：
10.1006/mcbr.2000.0223
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发表时间：
2000-05-01
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影响因子：
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通讯作者：
Glover, Claiborne V. C.
中科院分区：
文献类型：
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作者：
Bidwai, Ashok P.;Saxena, Amit;Glover, Claiborne V. C.
果蝇酪蛋白激酶II（CKII）由催化性α亚基和调节性β亚基组成。使用双杂交系统，我们已经分离出一些cDNA，这些cDNA与先前发表的编码β亚基的cDNA相关，但表现出不同的5'序列。为了确定这种序列变异的来源，我们分离了编码CKII β亚基的基因。β基因包含包含完整开放阅读框的五个外显子，以及5'非翻译区（UTR）中的五个替代外显子。每个cDNA中仅含有一个5' UTR外显子，这意味着五种不同的转录物。此外，β基因含有至少两个多聚腺苷酸加成信号，其在3'端产生额外的复杂性。复杂的转录模式可能在β亚基的空间和/或时间表达中起作用，因为除了一个例外，所有转录物都编码全长β多肽。果蝇、C. elegans和哺乳动物揭示了三个不变的内含子，以及最近的内含子获得/损失的证据。
Drosophila melanogaster casein kinase II (CKII) is composed of catalytic alpha and regulatory beta subunits. Using the two-hybrid system, we have isolated a number of cDNAs that are related to a previously published cDNA encoding the beta subunit, but exhibit divergent 5' sequences. To determine the source of this sequence variation, we have isolated the gene encoding the beta subunit of CKII. The beta gene contains five exons encompassing the complete open reading frame, as well as five alternative exons in the 5' untranslated region (UTR). Only one 5' UTR exon is contained in each cDNA, implying five distinct classes of transcript. In addition, the beta gene contains at least two poly(A) addition signals which generate additional complexity at the 3' end. The complex pattern of transcription may serve a role in the spatial and/or temporal expression of the beta subunit since, with one exception, all transcripts encode the full-length beta polypeptide. Phylogenetic comparison of the beta genes of Drosophila, C. elegans, and mammals reveals three invariant introns as well as evidence of recent intron gain/loss.